CHARLOTTE, N.C. (AP) — Penske Racing will take its appeal of penalties and fines against defending champion Brad Keselowski and teammate Joey Logano before a three-member NASCAR panel next week.

NASCAR selects the panel from a list of 48 people — former car owners, crew chiefs and drivers, as well as current track promoters and industry veterans. Their identities will not be revealed until after their decision, which can be appealed to NASCAR chief appellate officer John Middlebrook. The May 1 appeal will be conducted at the Research and Development Center in Concord.

The penalties have been one of the biggest stories of the season so far. NASCAR seized parts from the rear suspensions of both Penske cars during pre-race inspections at Texas, accusing the team of using unapproved parts in the rear housing.

All seven suspended employees were put on probation through Dec. 31. Penske officials say they are concerned that’s more than double the probation any previous infraction received.

Team owner Roger Penske told The Associated Press the parts were approved, but NASCAR alleged they had been modified before use.

“NASCAR has approved parts and unapproved parts. The parts that we had were approved parts, they are concerned that we modified them. That’s where the discussion is,” he said. “From an overall standpoint, NASCAR felt what we had provided them for approval, then these parts were different during the inspection process.”

Penske also said the team was working in a gray area of the rule book.

“I certainly don’t think it’s cheating,” Penske said. “You are looking at the rules and you are working in a gray area. We all work in the gray areas. We’re trying to be as competitive as we can be, we’ve got very creative minds and it takes a lot of creative minds to be competitive. There are many different areas we are all working on. We just looked at a particular rule that maybe NASCAR has a different view of. Now we’ll get a chance to have an unbiased panel look at it.”

Penske President Tim Cindric researched and found the three-member appeals panel has not overturned a NASCAR penalty regarding body infractions in the last three years. But, crew members are allowed to work during the appeal, and teams use the time to restructure and prepare for when the penalties are enforced.

Knaus had been punished for allegedly modifying sheet metal on Johnson’s car at Daytona. Middlebrook left intact the $100,000 fine against Knaus.

This time, NASCAR has not revealed many details of its case against Penske.

Teams very much were manipulating the rear suspensions of their cars last year, and NASCAR slowly addressed the issue through a series of technical bulletins issued over the course of the season. The rule book was specifically tightened this season, with added language to the passage demanding that all suspension systems and components must be presented “in a completed form/assembly” prior to being used in competition.

A second new passage clearly states, “all front end and rear end suspension mounts and mounting hardware must not allow movement or realignment of any suspension component beyond normal rotation or suspension travel.” That puts in writing that NASCAR will not tolerate teams altering the skew of the rear ends the way they did a year ago.

Penske said there was no prior warning from NASCAR that the team was potentially in violation of the rules, and that Logano’s car had already cleared tech at Texas before inspectors called him back after taking parts from Keselowski’s car. Logano barely made the start of the race.